I have to admit I've been struggling with this one for a while, most importantly because I haven't used GNOME 3 yet; I'm setting up my own little company right now, so time's a little short. As such, all I can do here is cover the arguments given - which, in my book, have both their strong as well as their weak points. Yes, GNOME 3 will not have buttons for minimising or maximising windows.

KDE has it, and I would argue they actually did it better than Microsoft for one simple reason: If you have a multi display setup, say 1280x1024 * 2, the snap feature works on 0 1280 and 2560 whereas in Windows it's only 0 and 2560.

While the windows don't snap between screen boundaries, you can still use the Win+arrows shortcuts to make a window snap on the right side of the left screen (and any other combination). I'm really not sure what would be the best approach here. On one hand, snapping on every screen edge would be more consistent. On the other hand having windows snap when trying to move them from one screen to another could get annoying.

While the windows don't snap between screen boundaries, you can still use the Win+arrows shortcuts to make a window snap on the right side of the left screen (and any other combination). I'm really not sure what would be the best approach here. On one hand, snapping on every screen edge would be more consistent. On the other hand having windows snap when trying to move them from one screen to another could get annoying.

KWin handles this quite nicely. Drag a window near a screen edge and a border appears to let you know the window will:
- maximise vertically and cover 50% of screen starting on that edge, or
- maximise to cover entire screen

With multiple monitors, the border will flicker over the right-hand 50% of left screen, then left-hand 50% of right screen, then disappear as you continue dragging.